Sure they would, if it would make them a buck. Lenovo for example already has separate models for pro ThinkPads with 'certified' Linux support versus the consumer line. Dell too. PC vendors already have 9000 SKUs, what's a few more?

Reminds me back in the day some vendors of Win 9x systems put something in the BIOS to prevent one from installing NT/2000. Gotta get the corporate model for that.